That's why I was asking... sometime even room temperature water doesn't reach the steaming point.

I like to heat up my water since the recipes sugests the oven be preheated... so should be the water._________________As a child my family's menu consisted of two choices: take it or leave it.
Buddy Hackett

This is what I usually do, use room temperature water when I first put in the batter to bake (it's ok since the batter is also at room temp). During the baking process, when the water level running low, I'll add "HOT" water to prevent sudden change in temperature to the cake batter.